The diff in the blocks is that the factory roller blocks have a taller lifter bore for the taller hydr roller lifters. Crane does make retrofit hydr roller cams that have a smaller base circle so that the lifters don't ride as high in the lifter bore. They make a good assortment of cams, many are identical to cams made for roller blocks, and are made for use with a steel distrib gear so no fast gear wear problems.
www.cranecams.com But, no, you can't use a "regular" roller block cam in a non-roller block.